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Submitted to: Arthropod Management Tests
Publication Type: Research Notes Publication Acceptance Date: 3/18/2014 Publication Date: 4/15/2014 Citation: Hesler, L.S. 2013. Efficacy of inorganic compounds against soybean aphid, laboratory tests 2012. Arthropod Management Tests. 38:F82. doi: 10.4182/amt.2013.M1 Interpretive Summary: Infestations by soybean aphids can reduce the yield of soybeans, and the efficacies of various compounds need evaluation to offer alternatives for soybean aphid control. Efficacy of various inorganic compounds was compared to that of a water check and conventional insecticides in two growth-chamber tests. Soybean test plants were infested when 10-d old (simple leaves fully expanded, first compound leaves unfurling) with 6 aphids and then caged. Plants were sprayed, and soybean aphids were counted on plants 11 (first test) or 10 days later. Post-spray counts of soybean aphids per plant differed among treatments. In the first test, soybean aphid counts on Milstop-treated plants did not differ from counts on plants treated with Pyganic insecticide. Soybean aphid counts after spraying with Fosphite or Nutrol did not differ from counts on plants sprayed with only water, and counts on Fosphite-treated plants did not differ from those on Milstop-treated plants. Fosphite-treated plants had moderately damaged, yellowed leaves within a few days after being sprayed. In the second test, the numbers of surviving soybean aphids on Milstop-treated plants did not differ from those on plants sprayed with water, but they were greater than counts on plants treated with Warrior II. Technical Abstract: Infestations by soybean aphids can reduce the yield of soybeans, and the efficacies of various compounds need evaluation for soybean aphid control. Efficacy of various inorganic compounds was compared to that of a water check and conventional insecticides in two growth-chamber tests. Soybean test plants were infested when 10-d old in the late VE stage (unifoliolate leaves fully expanded, first trifoliolate leaves newly expanding) with 6 aphids and then caged. Plants were sprayed, and soybean aphids were counted on plants 11 (first test) or 10 days later. Post-spray counts of soybean aphids per plant differed among treatments. In the first test, soybean aphid counts on Milstop-treated plants did not differ from counts on plants treated with Pyganic insecticide. Soybean aphid counts after spraying with Fosphite or Nutrol did not differ from counts on plants sprayed with only water, and counts on Fosphite-treated plants did not differ from those on Milstop-treated plants. Fosphite-treated plants had moderately yellowed leaves from apparent phytotoxicity within a few days after being sprayed. In the second test, the numbers of surviving soybean aphids on Milstop-treated plants did not differ from those on plants sprayed with water, but they were greater than counts on plants treated with Warrior II. |
